Artificial thread



- comprising 24% or 25% more or lessofcellulose d ."It' has been proposed ;to deluster threads severe, the "threads, were weakened andvery stances, when such a 'thread was treated with V 'characterizedby a low lusteroontemplated in- Patented July 17, 1934 mans An'rnucmn'rnmzm .Yan L Bohnson and HQ Swezey, Wayne:-

' hero, Va, assignors to DuPont RayonCompany,

intention relates to artificial thread i and more" particularly to the production of artificial thread. formedof cellulose acetate; which upon subsequent treatment with hot water or hot soap solution, such as 'at'orj near the boiling point ther'eoLorwith steam, 10585:? considerable portion'o'i i its: luster and assumes a dull: or "mat apnee a -,.i

one of the procedures now commonly em ployed' in the manufacture of artificialthread cellulose acetate dissolved acetone or amix ture of acetone and alcohol'yis spun, i.e. extruded through spinnere't, into an 'evaporatlve at'rziospheregfwhereby a thread of well-defined luster is produced. When a spinning solution aceta'te' i rf1aying an lacet'yl value, calculated as acetic id, of 5l%to dissolved'inacetone o n ian' d; alcohol,' is spun; the thread 25 form is" also characterized by a well-defined luster; The high luster or sheen-*makeS the thread admirably suitable for certain uses;

Howe' er; for certain uses where a lower subdued luster is "required, *thdustrdus thread is 'not appropriate. 1

ifjormedfof. cellulose acetate by subjecting-said threads in their normal state and appearanoe'to boiling solutions; such 'as wat'er' or soap solutions,

team. Where this treatment was long and often damaged. Afthrea'd formed of'cellulose acetate having an acetyl value calculated" as acetic acid o f 54% --to "55% iS Quit-e" resistant to delusteriiig by suc'h'treatmentjs: In man inboiling liquids; such as water or soap-solutions, even after 2" hours: treatment, the thread still possessed ,m r1 ee-,-1uster i Another *methodof preparing artificial thread corporatin'g in the' cellulose acetate spinning solution certain foreign-materials; suen' as nonsolvents, animal "or" vegetable oils, "wakes, higher esters or fatty acids; fv'arious wetting agents and dissolved salts. .'I 'hes e substances were per" mittedto remain in the f nal thread :or ,t've're removed therefrom by treatment with boiling water, soap solutions or other solvents, whereby voids" Werei forinedfin; the yarn yv'hich imparted t 3 New York, N. Y acorporation of Delaware No lh'aw'ing. Application M1 26;1'932,

I SerialNoJflw Y 12.oiai s. (o1. 10 46);

a dull or mat ;appearance. foreign substances and/or'thei-r'subsequent removal deleteriously afiected'the tensile strength of the thread, which was; or course, highly undesirable. '5 We have found that by" spinning a solution containing a plurality of cellulose acetates"haw ing different characteristics; such as different. acetyl values, difierent solubility characteristics or 'difl'erent actyl" values" and viscosities, there is produced afthread which, upon treatment with hot aqueous" fluids, 1 for "-example, steam or hot liquids, such aswater or soap solutions, atrornear" the boiling point thereon-will be readily delustered and the above-mentioned disadvantages-overcome. V It "is tl're'refore; an objectjot this invention to provide an artificial thread formed'of a plurality QicelIuIose-acetates' having difierent' char-ac teristics,-suoh as different acetyl values; difierent; stolubilities or different acetyl values and-viscosiieS. 'Anoth'er object of this inventio'ri is -t;o'"prov-ide a'ispi'nning solution' for preparlng a thread of the type mentioned inthe-preceding paragraph. 7 Additional objects will ppear 5 from-stile "fol lowing description and appended-claims. V i

"In carrying out the principles-of the einstant invention, there is prepared in any corrvenient manner a spinning solution of suitable viscosity and containing a plurality of cellulose acetates having different characteristics. This solution is spunacco'rding toQth-dry spinning process whereby a thread ofnormalluster is produced. This thread, either -'-p'rior to its fabrication into a -fabric orsubsequent to the weaving or knitting thereof, into cloth, if subjected to a hot aqueousifluid; for example; steam or hot liquids, such;as {water or soap slolutions, at' or ne'ar the boiling point thereof, will-be radilydlusteredl As has been mentioned, the spinning -solution, and"'therefore the 'tlrread 'produced'irom the same, contains a homogeneous mixture of a plurality of cellulose acetates-bf 'difie'rent characteri'stics. in the preferred embodir'nentzloftthe ues. Due tothe fact that the solubilities of "eel-5 may not, inaddition, difier from each other in their viscosities." v A I In accordancefwith' 'the principles of thisinpresence of-the invention; the cellulose acetates which are emplayed are characterized by difierent acetyl valscribed-as having different .solubilityjchara'cterl-stics. The, cellulose acetates employed, may. or

fect described may be obtained to some degree by a thread formed of 50% of a cellulose acetate having an acetyl value, calculated as "acetic acid, of 56%, and 50% of an acetate having an acetyl value, calculated as acetic acid, of 51% to 53%, the preferred embodiment contemplates a thread composed of 90% to 96% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 54% to 55% and 4% to 10% of a cellulose acetate having an-acetyl value, calculated as acetic acid, of 45% to 47%.

The acetates may beprepared according to the well-known procedures for making cellulose acetates by extending the hydrolysis of the primary acetate until an acetate of the desired acetyl value is secured.

The spinning solution containing the plurality of acetates of different characteristics may be produced in any well-known manner and of any desired concentration such as 24% to 25%. Usually the solvent or solvent mixture employed is of such a nature that the acetates are soluble therein. Due to this, a clearer and more homogeneous spinning solution is produced than that in which there is suspended or dispersed liquids or solids. As a consequence, spinning is less critical and less trouble is encountered. in the filtration and spinning of such a' solution. It is to be understood that by. the

term solvent is meant a single liquid possessing solvent properties or a mixture of liquids commonly termed a solvent mixture.

In order to more clearly explainthe nature of a the instant invention, the following specific illustrative examples are set forth: v

Example I.--A solution containing the following ingredients is spun by the ordinary dry spinning process:

Parts by weight Acetone 60.8

Alcohol (95%) 15.2

Cellulose acetate having an acetyl value,

calculated as acetic acid, of 54% 21.6

- Cellulose acetate having an acetyl value,

calculated as acetic acid, of 45% 2.4

position is spun by the usual evaporative process:

The thread, after being' reeled into ske ins, is immersed for 1 hour in a boiling 2% soap solution. After rinsing and drying, the yarn is found to have acquired a delustered appearance which is not so marked as that secured in the other examples.

Example Ill.A solution of the following ingredients is spun according to the dry spinning procedure:

Parts by weight Acetone 65 Water l0 Cellulose acetate having an acetyl value, calculated as acetic acid, of 54% to 55% Cellulose acetate having an acetyl value, calculated as acetic acid, of 45% to 48% 5 The thread, either in skein form or in fabric form, is treated with aboiling aqueous soap solution, and after rinsing and drying the yarn is found to possess an opaque and mat effect.

Though the invention is hereinbefore described in connection with a mixture of two acetates of different characteristics, it is to be understood that the invention is not restricted thereto, since it is obvious that morethan two acetates maybe used with equal success.

Since it is obvious that various changes and modifications may be made in the above descripinc tion without departing from the nature or spirit having an acetyl value, calculated as acetic.

acid, of 43% to 53%.

. r 2. An artificial thread having a normal luster,

which luster can be reduced by treatment witha hot aqueous fluid, and formed of a homogeneous mixture of cellulose acetates and comprising 90% to 96% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 54% to 55%, and 4% to 10% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 45% to 47%.

3. An artificial thread having a normal luster, which luster can be reduced by treatment with ahotaqueous fluid, andformed of a homogeneous mixture of cellulose acetates and comprising 90% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 54%, and 10% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 45%.

. 4. An artificial thread having a normal luster, which luster can be reduced by treatment with a hot aqueous fluid, and formed of a homogeneous mixture of cellulose acetates and'comprising equal parts by weight of a cellulose acetate having an acetyl value, calculated as acetic acid, of 56%, and a cellulose acetate having an acetyl value, calculated as acetic acid, of 51% to 53%.

5. An artificial thread having a normal luster, which luster can be .reducedby treatment with a hot aqueous fluid, and formed of a homogeneous mixture of cellulose acetates and comprising 80% of 'a cellulose acetate having an acetyl .value, calculated as acetic acid, of 54% to 55%, and 20% of a cellulose acetate having an acetyl .value of 45% to 48%.

6. A cellulose acetate spinning solution for producing a thread of normal luster, which iao luster is reduced by treatment with a hot aqueous fluid, comprising 50% to 95% by weight of a cellulose acetate having an acetyl value calculated as acetic acid, of 54% to 56%, and 5% to 50% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 43% to 53% dissolved in "a solvent, the proportions of the different acetates total combined quantities thereof.

7. A cellulose acetate spinning solution for producing a thread jof normal luster, which luster is reduced by treatment with a hot aqueous fluid, comprising 90% to 96% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 54%to 55%, and 4% to 10% of a cellulose acetate having an acetyl value, calculated as aceticacid, of to 47% dissolved in a solvent, the proportions of the different acetates being based on the total combined quantities thereof. 1 8. A cellulose acetate spinning solution for producing a thread of normal luster, which luster is reduced by treatment with a hot aqueous fluid, comprising 90% of a ..cellulose acetate having an acetyl value, calculated as acetic acid, of 54%, and 10% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 45% dissolved in a solvent, the proportions of the different acetates being based on the total combined quantities thereof.

9. A cellulose acetate spinning solution for producing a thread of normal luster, which luster is reduced by treatment with a hot aqueous fluid comprising equal parts by weight of a cellulose acetate having an'acetyl value, calculated as acetic acid, of 56%, and a cellulose acetate having an acetyl value, calculated as acetic acid,

being based on 1 the of 51% to 53% dissolved in a solvent, the pro portions of the different acetates being based on the total combined quantities thereof.

10. A cellulose acetate spinning solution for producing a thread of normal luster, which luster is reduced by treatment with a hot aqueous fluid, comprising of a cellulose acetate having an acetyl value, calculated as acetic acid, of- 54% to 55%, and 20% of a cellulose acetate having an acetyl value of 45% to 48% dissolved in a solvent, the proportions of the different acetates being based on the total combined quantities thereof.

'11. An artificial thread having a normal luster, which luster can be reduced by treatment with a hot aqueous fluid, and formed of a homogeneous mixture of cellulose acetates and comprising at least 50% by weight of a cellulose acetate having an acetyl value, calculated as acetic acid, of 54% -56% and notlover 50% by weight of a cellulose acetate having an acetyl value, calculated as acetic acid, of 43%53%.

12.'A cellulose acetate spinning solution for producing a thread of normal luster, which luster is reduced by treatment with a hot aqueous fluid, and formed of a homogeneous mix- 'ture of cellulose .acetates and comprising at least 50% value, calculated as acetic acid, of 54%56% and of a cellulose acetate having an acetyl not over 50% of a cellulose acetate having an acetyl value, calculated as acetic acid, of 43%- 53% dissolved in a solvent, the proportions of the different acetates being by weight and based on the total combined quantities thereof. 7

VAN L. BOHNSON. FENTON H. SWEZEY. 

